To date, integrated circuits (also referred to as ICs) each of which has semiconductor devices such as a diode and a transistor, and driving control circuits for the semiconductor devices integrated on one silicon substrate, have been developed. In particular, a lateral insulated gate bipolar transistor (LIGBT, hereinafter, simply referred to as a lateral semiconductor device) is a power transistor that includes a MOS input structure, and a bipolar output structure, and is a semiconductor that has an advantage that high power driving can be derived from less power with its high voltage and current semiconductor properties.
The lateral semiconductor device has a characteristic that conductivity modulation is enhanced in a drift region in an on-state, thereby obtaining a low on-voltage (on-resistance). For example, a technique disclosed in Patent Literature 1 represents an example of the lateral semiconductor device.